"Fine to coarse or pebbly, commonly feldspathic, cross laminated and channel bedded sandstone. The base often channels into the beds below. The sandstone is locally interbedded with thin mudstones. The Hollin Rock Member represeents a widespread deltic sandstone body, or series of bodies, within the Flintshire Coalfield, and may record a period of distributary channel and mouth bar advances at a time of lowered sea level."@en . . "The type section shows a sharp contact between hard, white sandstone and overlying seat earth (fireclay), about 3 m below base of the Etruria Formation."@en . "stable"@en . . "The type section displays a sharp base of grey sandstone overlying dark mudstones with ironstones, about 4.44m above top of Massy (Drowsell) Coal (J500 of British Coal). Elsewhere the base channels down in places to below the Hollin Coal (H800 of British Coal)."@en . "314.75"^^ . "310.0"^^ . . . "Hollin Rock"@en . . "Up to 75 thick."@en . . "Hollin Rock"@en . . "Sandstone with subsidiary mudstone. Stratified bedrock. Occurs onshore. Deposited during the Bolsovian Substage (Carboniferous Period) (314.75-310 Ma BP)."@en . "HLR"@en . .